Sunday July 10, 2016

In what is being dubbed "visual impairment intracranial pressure syndrome," astronauts are experiencing worsened vision and physical changes to their eyes (such as inflamed optic nerves and stretchmark-like folds) after being in space. The cause of this may be the lack of gravity, which results in extra fluid in the skull that increases pressure on the brain and eye.

In 2005, astronaut John Phillips took a break from his work on the International Space Station and looked out the window at Earth. He was about halfway through a mission that had begun in April and would end in October. When he gazed down at the planet, the Earth was blurry. He couldn’t focus on it clearly. That was strange آ— his vision had always been 20/20. He wondered: Was his eyesight getting worse? "I’m not sure if I reported that to the ground," he said. "I think I didn’t. I thought it would be something that would just go away, and fix itself when I got to Earth." It didn’t go away. During Phillips’ post-flight physical, NASA found that his vision had gone from 20/20 to 20/100 in six months.